最近我将 recyclerview-v7:23 升级为 recyclerview-v7:24.2.0 . 我的应用程序有一个无尽的滚动列表 . 当我将加载视图添加到 RecyclerView 时，错误消息指向 notifyItemInserted 行（null对象表示正在加载，id 0为空，-1表示页面结束）并且之前工作正常（recyclerview-v7：23）但突然间我得到这样的错误，并以某种方式我的加载出现两次然后当它删除一个，有一个加载仍然可见在顶部 .
W/RecyclerView: Cannot call this method in a scroll callback. Scroll callbacks might be run during a measure & layout pass where you cannot change the RecyclerView data. Any method call that might change the structure of the RecyclerView or the adapter contents should be postponed to the next frame.java.lang.IllegalStateException:
at android.support.v7.widget.RecyclerView.assertNotInLayoutOrScroll(RecyclerView.java:2403)
at android.support.v7.widget.RecyclerView$RecyclerViewDataObserver.onItemRangeInserted(RecyclerView.java:4631)
at android.support.v7.widget.RecyclerView$AdapterDataObservable.notifyItemRangeInserted(RecyclerView.java:10469)
at android.support.v7.widget.RecyclerView$Adapter.notifyItemInserted(RecyclerView.java:6211)
at com.sketchproject.infogue.fragments.MessageFragment.loadMessages(MessageFragment.java:109)
at com.sketchproject.infogue.fragments.MessageFragment.access$100(MessageFragment.java:42)
at com.sketchproject.infogue.fragments.MessageFragment$1.onLoadMore(MessageFragment.java:87)
at com.sketchproject.infogue.modules.EndlessRecyclerViewScrollListener.onScrolled(EndlessRecyclerViewScrollListener.java:74)
当我删除部分错误（添加加载）它再次正常工作，我不知道为什么，是较新版本的recyclerview阻止将数据添加到适配器太快或有回调函数，当“测量和布局”时触发recyclerview完了，这是我的代码
private void loadArticles(final int page) {
if (!isEndOfPage && apiArticleUrl != null) {
if (swipeRefreshLayout == null || !swipeRefreshLayout.isRefreshing()) {
allArticles.add(null);
articleAdapter.notifyItemInserted(allArticles.size() - 1); // error here
}
JsonObjectRequest articleRequest = new JsonObjectRequest(Request.Method.GET, apiArticleUrl, null,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
String status = response.getString("status");
JSONObject articles = response.getJSONObject("articles");
String nextUrl = articles.getString("next_page_url");
int currentPage = articles.getInt("current_page");
int lastPage = articles.getInt("last_page");
JSONArray data = articles.optJSONArray("data");
apiArticleUrl = nextUrl;
if (status.equals(APIBuilder.REQUEST_SUCCESS)) {
if (swipeRefreshLayout == null || !swipeRefreshLayout.isRefreshing()) {
allArticles.remove(allArticles.size() - 1);
articleAdapter.notifyItemRemoved(allArticles.size());
} else {
swipeRefreshLayout.setRefreshing(false);
int total = allArticles.size();
for (int i = 0; i < total; i++) {
allArticles.remove(0);
}
articleAdapter.notifyItemRangeRemoved(0, total);
}
List<Article> moreArticles = new ArrayList<>();
if (data != null) {
for (int i = 0; i < data.length(); i++) {
JSONObject articleData = data.getJSONObject(i);
Article article = new Article();
article.setId(articleData.getInt(Article.ID));
article.setSlug(articleData.getString(Article.SLUG));
article.setTitle(articleData.getString(Article.TITLE));
article.setFeatured(articleData.getString(Article.FEATURED_REF));
article.setCategoryId(articleData.getInt(Article.CATEGORY_ID));
article.setCategory(articleData.getString(Article.CATEGORY));
article.setSubcategoryId(articleData.getInt(Article.SUBCATEGORY_ID));
article.setSubcategory(articleData.getString(Article.SUBCATEGORY));
article.setContent(articleData.getString(Article.CONTENT));
article.setContentUpdate(articleData.getString(Article.CONTENT_UPDATE));
article.setPublishedAt(articleData.getString(Article.PUBLISHED_AT));
article.setView(articleData.getInt(Article.VIEW));
article.setRating(articleData.getInt(Article.RATING_TOTAL));
article.setStatus(articleData.getString(Article.STATUS));
moreArticles.add(article);
}
}
int curSize = articleAdapter.getItemCount();
allArticles.addAll(moreArticles);
if (allArticles.size() <= 0) {
Log.i("INFOGUE/Article", "Empty on page " + page);
isEndOfPage = true;
Article emptyArticle = new Article(0, null, "Empty page");
allArticles.add(emptyArticle);
} else if (currentPage >= lastPage) {
Log.i("INFOGUE/Article", "End on page " + page);
isEndOfPage = true;
Article endArticle = new Article(-1, null, "End of page");
allArticles.add(endArticle);
}
articleAdapter.notifyItemRangeInserted(curSize, allArticles.size() - 1);
} else {
Log.i("INFOGUE/Article", "Error on page " + page);
Helper.toastColor(getContext(), R.string.error_unknown, R.color.color_warning_transparent);
isEndOfPage = true;
Article failureArticle = new Article();
failureArticle.setId(-2);
failureArticle.setTitle(getString(R.string.error_unknown));
allArticles.add(failureArticle);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
if (swipeRefreshLayout != null && swipeRefreshLayout.isRefreshing()) {
swipeRefreshLayout.setRefreshing(false);
}
// remove last loading
allArticles.remove(allArticles.size() - 1);
articleAdapter.notifyItemRemoved(allArticles.size());
String errorMessage = getString(R.string.error_unknown);
NetworkResponse networkResponse = error.networkResponse;
if (networkResponse == null) {
if (error.getClass().equals(TimeoutError.class)) {
errorMessage = getString(R.string.error_timeout);
} else if (error.getClass().equals(NoConnectionError.class)) {
errorMessage = getString(R.string.error_no_connection);
}
} else {
if (networkResponse.statusCode == 404) {
errorMessage = getString(R.string.error_not_found);
} else if (networkResponse.statusCode == 500) {
errorMessage = getString(R.string.error_server);
} else if (networkResponse.statusCode == 503) {
errorMessage = getString(R.string.error_maintenance);
}
}
Helper.toastColor(getContext(), errorMessage, R.color.color_danger_transparent);
// add error view holder
isEndOfPage = true;
Article errorArticle = new Article();
errorArticle.setId(-2);
errorArticle.setTitle(errorMessage);
allArticles.add(errorArticle);
}
}
);
articleRequest.setTag("articles");
articleRequest.setRetryPolicy(new DefaultRetryPolicy(
APIBuilder.TIMEOUT_SHORT,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
VolleySingleton.getInstance(getContext()).addToRequestQueue(articleRequest);
}
}
该代码是从onCreate方法调用的
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_article_list, container, false);
// Set the adapter
if (view instanceof RecyclerView) {
Context context = view.getContext();
recyclerView = (RecyclerView) view;
// determine column of list
LinearLayoutManager linearLayoutManager;
if (mColumnCount <= 1) {
linearLayoutManager = new LinearLayoutManager(context);
} else {
linearLayoutManager = new GridLayoutManager(context, mColumnCount);
}
// if article list authored by logged user then prefer editable view holder
if (mMyArticle) {
articleAdapter = new ArticleRecyclerViewAdapter(allArticles, mArticleListListener, mArticleEditableListener);
} else {
articleAdapter = new ArticleRecyclerViewAdapter(allArticles, mArticleListListener, hasHeader);
}
// set the adapter and attach custom scroll listener that triggered onLoadMore() and onReachTop()
recyclerView.setAdapter(articleAdapter);
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.addOnScrollListener(new EndlessRecyclerViewScrollListener(linearLayoutManager) {
@Override
public void onLoadMore(final int page, int totalItemsCount) {
if (!isFirstCall) {
loadArticles(page);
}
}
@Override
public void onReachTop(boolean isFirst) {
// activate swipe function when list reach top only, find out where do fragment attached
if (getActivity() instanceof ArticleActivity) {
((ArticleActivity) getActivity()).setSwipeEnable(isFirst);
} else if (getActivity() instanceof ApplicationActivity) {
((ApplicationActivity) getActivity()).setSwipeEnable(isFirst);
}
}
});
if (isFirstCall) {
isFirstCall = false;
loadArticles(0);
}
}
return view;
}
我的问题是：
-
问题是否来自
RecyclerView的新版本？ -
在滚动侦听器中实现
notifyItemInserted是错误的吗？以前工作过 . -
如何解决这个问题？
Updated
when I logged the code inside first call and scroll,
09-12 03:49:10.078 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers URL http://192.168.43.141:8000/api/contributor/support/followers?contributor_id=1
09-12 03:49:26.421 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers first call
09-12 03:49:26.421 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers URL http://192.168.43.141:8000/api/contributor/support/followers?contributor_id=1
09-12 03:49:26.617 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers second call (scroll)
09-12 03:49:26.618 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers URL http://192.168.43.141:8000/api/contributor/support/followers?contributor_id=1
09-12 03:49:27.365 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers second call (scroll)
它们在第一次加载时被调用两次，在第一次调用后添加加载视图以某种方式触发滚动并再次调用 .
4 回答
在某些情况下onScrollStateChanged可能就足够了
您也可以使用Google Play服务的Tasks API
您也可以使用视图发布 .
2和3.您在设置时无法更改项目（通过调用onBindViewHolder） . 在这种情况下，您必须通过调用Handler.post（）在当前循环结束时调用notifyItemInserted
我希望，它会解决你的问题 .